CN109878175B

CN109878175B - PVDF pipe with anti-corrosion effect and processing technology thereof

Info

Publication number: CN109878175B
Application number: CN201910068529.XA
Authority: CN
Inventors: 朱圣才; 谢海燕
Original assignee: Wuhan Gaozheng New Material Technology Co ltd
Current assignee: Wuhan Gaozheng New Material Technology Co ltd
Priority date: 2019-01-24
Filing date: 2019-01-24
Publication date: 2021-03-19
Anticipated expiration: 2039-01-24
Also published as: CN109878175A

Abstract

The invention relates to a PVDF pipe with anti-corrosion effect and a processing technology thereof, comprising an inner layer and an outer layer, wherein the inner layer is made of modified PVDF, and the outer layer is made of PVC. The processing technology provided by the invention is simple to operate, and the prepared PVDF pipe has high corrosion resistance and good durability.

Description

PVDF pipe with anti-corrosion effect and processing technology thereof

Technical Field

The application relates to a PVDF pipe and a processing technology thereof, in particular to a PVDF pipe with an anti-corrosion effect and a processing technology thereof.

Background

The PVDF polyvinylidene fluoride is semitransparent or white powder or particles in appearance, has tightly arranged molecular chains and stronger hydrogen bonds, has an oxygen index of 46 percent, is non-combustible, has the crystallinity of 65 to 78 percent and the density of 1.77 to 1.80g/cm³The melting point is 172 ℃, the thermal deformation temperature is 112-145 ℃, and the long-term use temperature is-40-150 ℃.

The PVDF pipe in the prior art has poor corrosion resistance and poor durability.

Disclosure of Invention

In order to solve the defects of the prior art, the invention relates to a PVDF pipe with an anti-corrosion effect and a processing technology thereof.

The purpose of the invention is realized by the following technical scheme

The PVDF pipe with the anti-corrosion effect comprises an inner layer and an outer layer, wherein the inner layer is made of modified PVDF, and the outer layer is made of PVC.

The invention also provides a processing technology of the PVDF pipe with the anti-corrosion effect, which comprises the following steps:

s1, granulation: granulating modified PVDF master batch and PVC master batch;

s2, heating: respectively heating and melting the PVDF master batch and the PVC master batch by a single-screw extruder to extrude;

s3, extruding into a pipe: and (4) passing the two kinds of master batches melted in the step S2 through an annular splitter, and finally extruding the master batches into a tube through an annular die.

And S4, cooling and forming, namely cooling and shaping the pipe in the step S3 through a cooling rod and cutting the pipe into fixed lengths to obtain the anti-corrosion PVDF pipe.

Based on the technical scheme, each layer of the PVDF pipe extruded by the annular flow divider is the PVC outer layer, so that the anticorrosion effect of the PVDF pipe is good, and the PVDF pipe prepared by the process has good durability.

Further, the specific process of step S1 is adding PVDF, PMMA, titanium dioxide and auxiliary agent into a high-speed mixer, mixing uniformly, adding into a granulator, performing electric heating extrusion and drying with an air dryer, granulating with a granulator to obtain modified PVDF masterbatch, adding PVC into the granulator, performing electric heating extrusion and drying with an air dryer, and granulating with a granulator to obtain PVC masterbatch

Based on the technical scheme, the PVDF has good chemical corrosion resistance, high temperature resistance, oxidation resistance, weather resistance, ray radiation resistance, special performances such as piezoelectricity, dielectricity, pyroelectricity and the like. PMMA acts as a binder for the mixture. The titanium dioxide plays a role in coloring, so that the tube is white. The antioxidant consumes free oxygen in the raw materials in the processing process, and ensures that the raw materials are not oxidized. The toughening agent plays a role in strengthening toughness.

Further, in the step S1, the mass ratio of PVDF, PMMA, titanium dioxide and the auxiliary agent is 50-60:20-30:5-15: 5.4-15.

Further, in step S1, the auxiliary agent includes one or more of a toughening agent, an antioxidant, or a filler calcium carbonate.

Based on the technical scheme, the antioxidant consumes free oxygen in the raw materials in the processing process, so that the raw materials are not oxidized, and the toughening agent plays a role in enhancing toughness.

Further, in step S1, the temperature of the electric heating is 180-230 ℃.

Further, in step S3, the annular splitter has a double-layer inlet, the inner layer inlet passes through the fused modified PVDF masterbatch, the outer layer inlet passes through the fused PVC masterbatch, and finally the pipe is extruded through an annular die.

The invention has the beneficial effects that

The processing technology provided by the invention is simple to operate, and the prepared PVDF pipe has high corrosion resistance and good durability.

Detailed Description

The principles and features of this invention are described below in conjunction with examples which are set forth to illustrate, but are not to be construed to limit the scope of the invention.

Example 1

Adding 50kg of PVDF, 20kg of PMMA, 5kg of titanium dioxide and 5.4kg of toughening agent into a high-speed mixer, uniformly mixing, then adding into a granulator, drying by an air dryer after electric heating extrusion at 180 ℃, finally granulating by a granulator to obtain modified PVDF master batches, adding PVC into the granulator, drying by the air dryer after electric heating extrusion, and finally granulating by the granulator to obtain PVC master batches; respectively carrying out electric heating melting extrusion on the modified PVDF master batch and the PVC master batch through a single-screw extruder; then passing through a double-layer inlet of the annular splitter, passing through the fused modified PVDF master batch at an inner layer inlet, passing through the fused PVC master batch at an outer layer inlet, and finally extruding into a pipe through an annular mouth mold. Finally, cooling and shaping the pipe by a cooling rod and cutting the pipe into fixed lengths to obtain the anti-corrosion PVDF pipe

The PVDF pipe prepared by the process has good corrosion resistance effect, good durability, improved toughness, good mixing uniformity among various raw materials, white produced pipe and good aesthetic property.

Example 2

Adding 60kg of PVDF, 30kg of PMMA, 15kg of titanium dioxide and 15kg of antioxidant into a high-speed mixer, uniformly mixing, then adding into a granulator, electrically heating and extruding at 230 ℃, drying by using an air dryer, finally granulating by using a granulator to obtain modified PVDF master batches, adding PVC into the granulator, electrically heating and extruding, drying by using the air dryer, and finally granulating by using the granulator to obtain PVC master batches; respectively carrying out electric heating melting extrusion on the modified PVDF master batch and the PVC master batch through a single-screw extruder; then passing through a double-layer inlet of the annular splitter, passing through the fused modified PVDF master batch at an inner layer inlet, passing through the fused PVC master batch at an outer layer inlet, and finally extruding into a pipe through an annular mouth mold. And finally, cooling and shaping the pipe by a cooling rod and cutting the pipe into fixed lengths to obtain the anti-corrosion PVDF pipe.

Example 3

Adding 57kg of PVDF, 23kg of PMMA, 10kg of titanium dioxide, 2kg of toughening agent and 5.5kg of antioxidant into a high-speed mixer, uniformly mixing, then adding into a granulator, electrically heating and extruding at 200 ℃, drying by using an air dryer, finally granulating by using a granulator to obtain modified PVDF master batches, adding PVC into the granulator, electrically heating and extruding, drying by using the air dryer, and finally granulating by using the granulator to obtain PVC master batches; respectively carrying out electric heating melting extrusion on the modified PVDF master batch and the PVC master batch through a single-screw extruder; then passing through a double-layer inlet of the annular splitter, passing through the fused modified PVDF master batch at an inner layer inlet, passing through the fused PVC master batch at an outer layer inlet, and finally extruding into a pipe through an annular mouth mold. And finally, cooling and shaping the pipe by a cooling rod and cutting the pipe into fixed lengths to obtain the anti-corrosion PVDF pipe.

Comparative example 1

Adding 57kg of PVDF into a high-speed mixer, uniformly mixing, then adding into a granulator, drying at 200 ℃ by an air dryer through electric heating extrusion, and finally granulating by a granulator to obtain PVDF master batches, adding PVC into the granulator, drying by the air dryer through electric heating extrusion, and finally granulating by the granulator to obtain PVC master batches; respectively heating and melting the PVDF master batch and the PVC master batch by a single-screw extruder to extrude; finally, the mixture is extruded into a tube through a die. And finally, cooling and shaping the pipe by a cooling rod and cutting the pipe into fixed lengths to obtain the anti-corrosion PVDF pipe.

The pipe manufactured through the process is poor in toughness, poor in corrosion prevention effect and not white enough in appearance.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The processing technology of the PVDF pipe with the anti-corrosion effect is characterized by comprising the following steps:

s1, granulation: granulating modified PVDF master batch and PVC master batch;

s3, extruding into a pipe: enabling the two melted master batches in the step S2 to pass through an annular splitter, and finally extruding the master batches into a tube through an annular die;

s4, cooling and forming, namely cooling and shaping the pipe in the step S3 through a cooling rod and cutting the pipe into fixed lengths to obtain an anti-corrosion PVDF pipe;

the PVDF pipe comprises an inner layer and an outer layer, wherein the inner layer is made of modified PVDF, and the outer layer is made of PVC;

step S1 is a concrete process, PVDF, PMMA, titanium dioxide and auxiliary agent are added into a high-speed mixer to be mixed evenly, then the mixture is added into a granulator to be subjected to electric heating extrusion and blow-drying by an air dryer, finally, a granulator is used for cutting into particles to obtain modified PVDF master particles, PVC is added into the granulator to be subjected to electric heating extrusion and blow-drying by the air dryer, and finally, the particles are cut by the granulator to obtain PVC master particles;

in the step S1, the mass ratio of PVDF, PMMA, titanium dioxide and auxiliary agent is 50-60:20-30:5-15: 5.4-15;

and S3, passing the fused modified PVDF master batch through the inner layer inlet and the fused PVC master batch through the outer layer inlet, and finally extruding the mixture into a pipe through an annular die.

2. The process for processing PVDF pipes with anticorrosion effect as claimed in claim 1, wherein the assistant in step S1 comprises one or more of toughening agent, antioxidant or calcium carbonate as filler.

3. The process for producing PVDF tubing having anti-corrosion effect as defined in claim 1, wherein the temperature of electrical heating in step S1 is 180-230 ℃.